Vacuum-pump



A. H. DODD. VACUUM PUMP.

(No Model.)

No. 470,847. Patented Mar. 15, 1892.

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UNITED STATES ATENT FFICE.

ALVIN H. DODD, OF DENVER, COLORADO.

VACUUM-PUMP.

SPECIFICATION forming part of Letters Patent No. 470,847, dated March15, 1892.

Application filed April 27, 1891. Serial No- 390,624. (No model.)

To aZZ whom it may concern:

Be it known that I, ALVIN H. DODD, of Denver, in the county of Arapahoeand State of Colorado, have invented a new and useful Improvement inVacuum-Pumps, of which the following is a specification.

My invention relates to an improvementiu vacuum-pumps in which thepressure of the live steam upon the liquid in one of two cylinders todischarge the same sprays a portion of the liquid into the steam-filledcylinder from which the liquid has been discharged, and thereby producesa vacuum and causes the refilling of the other cylinder.

The object of my present invention is to provide a simple and economicalstructure and arrangement of the cylinders and the chamber whichconnects their bases and to provide means whereby the liquid in thedischarge-chamber will serve to form a partial vacuum in the cylinderfrom which the liquid has just been discharged and thereby effect thethrow of the valve to admit live steam to the liquid-filled cylinder.

A practical embodiment of my invention is represented in theaccompanying drawings, in which Figure 1 is a view in side elevation,partly in section. Fig. 2 is a top plan view of the base-plate, showingin dotted lines the positions of the sub-chambers and discharge-conduits,the cylinders themselves being removed. Fig. 3 is a viewinhorizontal section through line a; so of Fig. 1, and Fig. 4 is asectional view in detail of one of the feeding-valves leading from thecylinder to the sprayerchamber.

A and A represent the two cylinders, which are preferably formed, asshown, tapering and with rounded tops and short necks a and a on theupper adjacent edges, to which the branches 1) and b of thevalve-chamberB are bolted, so as to establish communication between thevalve-chamber and each of the cylinders.

The valve-chamber B is provided with a bore extendingtherethrough fromend to end, in which is seated the valve, comprising a pair of pistons Oand 0, connected bya stem 0. Steam-ports c and 0 lead from pointsintermediate of the ends of the chamber B to the cylinders A and A,respectively, and another set of ports 0 and 0 lead from the cylinders Aand A, respectively, to the ends of the valve-chamber B. The caps D andD, which close the opposite ends of the valvechainber B, are providedwith lugs d and d, which enter a short distance within the ends of thevalve-chamber and serve to stop the movement of the valve before itreaches the end of the valve-chamber, so that there is always opencommunication between the ends of the valve-chamber and the interiors ofthe respective cylinders. Steam. is admitted to the central portion ofthe valve-chamber, so as to enter the ports cand 0 when either one isuncovered by the pistons O, by a steam-,

inlet pipe E.

The cylinders A and A are provided at their bases with outwardly-turnedflanges a a by means of which they are bolted to seats f and f on theupper face of the base F. The base F is made hollow and separated intochambers and conduits, as follows: The common inlet-pipe for the liquidis represented at G and communicates through passages g and g withopenings g and g through into the bases of the cylinders. The openings gand g are provided with valves g and g which open upwardly into thecylinder to admit water from the inlet-pipe G when the pressure isremoved from their upper sides and to prevent its return when pressureis exerted upon their upper sides.

A seat h for the discharge-chamber H is provided in proximity to theseats for the cylinders A and A and preferably upon the same basetherewith, and communication is established between the bases of thecylinders and the discharge-chamber by means of openings I and I throughthe bottoms of the cylinders into passages 2' and i, which lead thenceto the base of the discharge-chamber H and open upwardly into it throughopenings h and k provided with upwardly-opening valves h and b There isalso provided in connection with the discharge-chamber and the cylindersa sub-chamber K, of anchor form, which communicates with the interiorspfthe two cylinders around the outer portions of their bases throughseries of upwardly-projected spray-nozzles 7c, in the present instancefour being represented in the bottom of each cylinder. There are alsoprovided what I am ICO pleased to term spray-feeders or spraysupplyvalves, comprising a series of openings 7c, here shown as grouped incircular form and adapted to be opened and closed by avertically-movable valve L, fixed to a stem Z. The valve L closesupward, so that when there is pressure within the cylinders A and A thesaid valve will remain open and allow the liquid to flow down through itinto the sub-chamber K; but when the pressure is removed from within thecylinder the said valve L will close and prevent the return of liquidfrom the sub-chamber K up into the cylinder.

The spray-nozzles k are at all times open, so that when there ispressure exerted upon the liquid in the sub-chamber K and the press ureis removed from within the cylinder the liquid within the sub-chamberwill be forced upwardly through the spray-nozzles it in the form of jetswithin the cylinder. There is also apermanent opening M through thebottom of the discharge-chamber ll into the subchamber K, so that thepressure of the liquid within the discharge-chamber will tend to exert aback-pressure into the sub-chamber K, and hence will tend to throw theliquid upwardly into the jet-nozzles when the pressure is removed withinthe cylinder.

The cylinders A and A are provided at their upper ends with doors N andN for gaining access to the cylinders when desired.

In operation suppose the cylinderA to have been filled with liquid andthe liquid to have been discharged from the cylinder A. As soon as theliquid being discharged in A has reached a point below the spray-nozzles7s, exposing the iron surface of the base, the steam will be therebysufficiently condensed to reduce the pressure in that cylinder and startthe valve to admit steam into the other cylinder, or the steam may bemomentarily cut off by well-known or suitable cut-cit devices, (notshown herein,) and the back-pressure from the discharge-chamber 11 uponthe liquid in the sub-chamber K will force jets of the liquid up throughthe spray-nozzles 7t in the cylinder A, and thereby form a partialvacuum, snfiicient to complete the throw of the valve in the chamber 13over into the position shown in Fig. 3, thereby closing the entrance oflive steam to the cylinderA'and admitting it to the cylinder A throughthe ports 0. The pressure of thelive steam upon the liquid in the filledcylinder A will discharge the same through the opening I and channel tinto the discharge-chamber and will at the same time exert a pressureupon the liquid in the sub-chamber K, forcing jets through thespray-nozzles 7a in the cylinder A and completing the condensation ofsteam therein, and thereby forming a vacuum and allowing the same tofill through the valveopening 9 The same operation will take place inreverse order when the liquid in the cylinder A has been lowered to apoint below the spray-nozzles 7.: in that cylinder.

That I claim as my invention is- 1. The combination of the cylinders, adischarge-chamber in direct communication with the cylinders, asub-chamber having a valved communication withthe cylinders and an opencommunication with the discharge-chamber, and spraying-nozzles uprisingfrom the subchamber into the bottoms of the cylinders, substantially asset forth.

2. The combination of cylinders having a tapered form, rounded tops, andoutwardlyturned flanges at their bases, a dischargechamber, a hollowbase-section forminga seat for the cylinders and discharge-chamber, andasub-chamberin said hollow base-section, the cylinders having directcommunication with the discharge-chamlmr and sub-chamber and saidsub-chamber having a direct communication with the discharge-chamber,substantially as set forth.

8. The combination of cylinders, a discharge-chamber, a sub-chamberextending along under the periphery of the bases of the cylinders, andspraying-nozzles arranged around the said periphery and extending fromthe sub-chamber up into the bottoms of the cylinders, the cylinderscommunicating directly with the discharge-chamber and the sub-chamberand the sub-chamber having a direct communication with the dischargechamber, substantially as set forth.

In testimony whereof I have signed my n ame in the presence of twosubscribing witnesses.

ALVIN ll. DODD.

Vitnesses:

WM. R. IloWLANn, WM. G. RUSSELL.

